With the development of display technology, liquid crystal display has become the most commonly used flat panel display device.
The liquid crystal display comprises an array substrate and a color film substrate. The array substrate is provided with a plurality of sub pixel units arranged in an array, and with gate lines and data lines arranged in a criss-cross pattern for separating each sub pixel unit. The array substrate is usually provided with common electrode lines parallel to the gate lines. The color film substrate is provided with a color film and a black matrix, the location of the color film layer corresponding to sub pixel units of the array substrate, and the location of the black matrix corresponding to the region of the array substrate outside the sub pixel units, i.e., the region of the gate lines, data lines and common electrode lines, to prevent light from leaking through the region of the array substrate outside the sub pixel units.
The area of black matrix in existing liquid crystal display device is relatively large so as to completely cover the gate lines, data lines and common electrode lines as well as other parts. Therefore, there exists the technical problem of low aperture ratio in the existing liquid crystal display device.